First of all, you are sweet to go to the trouble of researching this.
I would absolutely recommend either the 5 quart or 7 quart Le Creuset french ovens.
If she's really into cooing, she'll use it alllllllllll the time. And, she'll have it forever, and then her kids or grandkids will have it.
It's top quality that has little rival -- something that can't always be said for other kinds of cookware. You can have endless debates about the merits of a brand of SS saucepan, for example.
A KA mixer, like VT suggested, is also a wonderful thing to have in the kitchen.
If she doesnt have a food processor, though, that would be my top choice. A cook cannot live without one.